ATRAC3 superior or inferior to mp3 ?
Reply #20 – 2004-07-13 00:38:58
Oops, I missed a serious flaw in the two tests linked above : one of them was run with 4 musical samples given by Sony, and only 1 chosen by the lab, and in the other, 7 samples were chosen by Sony, while 3 were chosen by the lab. It is likely, Sony having very big interests in the ATRAC success, that they gave musical samples especially chosen so as to advantage ATRAC over other codecs. Thus there might be a strong bias for ATRAC in both tests. [a href="index.php?act=findpost&pid=224287"][{POST_SNAPBACK}][/a] You've maybe missed this other important flaw:1.3 - Listening test material All Atrac3 and Atrac3plus files were encoded and converted by Sony Corporation. The Laboratory takes on trust that these files were encoded with good intention and at the correct bitrate. Highly scientific approach Samples came from Sony, encoded material from Sony, headphones from Sony. I wonder if listeners are not also from Sony . Anyway, they didn't precise the mp3 settings used. Are files in full-stereo like Atrac3 at the same bitrate? Could be possible. Other important thing to precise: the frequency graphs at the end of the report (APPENDIX III) are showing a strange cut-off behaviour of atrac3plus: - 20 Khz lowpass with atrac3plus@48 kbps - 21 Khz lowpass with atrac3plus@64 kbps - 22 Khz lowpass with atrac3@132 kbps If you look on the lowpass used in commercial atrac3/atrac3plus encoders, these values are totally different - ~18 Khz for atrac3@132 - not sure for the other, but it must be something like 16 KHz for 64kbps and 14 KHz for 48 kbps. These graphs are very important: they are proving either that encoders used for this test are totally different from encoders available for MD users via SonicStage or they are proving that Sony didn't respected the bitrate asked for this test.